Stand-alone printers have become increasingly popular for document printing at the work place and home. These printers typically employ a toner supply device (such as a toner cartridge) provided with a corona wire for image formation processing.
A problem with these stand-alone printers is the accumulation of excess toner and other debris on the corona wire. These accumulations are burned onto the corona wire due to the high voltage placed on the corona wire during operation. These accumulations can deteriorate the printer quality and can interrupt the continuous use of these printers by causing print defects, such as smudging or dark streaks on the printed pages. For some cases, these defects could be cured by simply wiping the debris from the small thin corona wire in the printer toner cartridge. To address this simple problem and allow maximum working time, cleaning apparatus were developed that allow the user to clean the corona wire.
For example, in the IBM LaserPrinter Series toner cartridge, a long narrow plastic arm extends the width of the printer cartridge (i.e., the length of the corona wire) and includes a seat residing at one end of the arm. This seat houses a felt piece that wraps around the corona wire. The other end of this arm includes a handle that protrudes from the side of the printer cartridge, allowing the user to access and manipulate the plastic arm. When the corona wire needs to be cleaned, the user holds the handle and pulls the long plastic arm out from the side of the cartridge causing the felt piece to slide along the length of the corona wire. The toner and other debris accumulated on the corona wire adheres to the felt piece or is pushed off or along the wire.
Other types of cartridge cleaning apparatus include a member that is pressed upward against the wire for the purpose of cleaning the corona wire, as described in U.S. Pat. No. 4,788,573 to Nakaoka, et al. The teachings of this patent are incorporated herein by reference. The pressure force imparted by the upper pressing of these types of cleaning cartridge must be predetermined and controlled to ensure that the corona wire is not broken.
The problem with these cartridge cleaning apparatus is that only the loose toner and debris is cleaned from the corona wire. The toner that has burned onto the corona wire due to the high voltage placed on the corona wire during operation is not removed by felt type cleaners.